The bottom bar is located under the timeline and brings additional buttons and information.
The buttons allow to change the view of the timeline and the behaviour mode of neighbour sheets.
The options on the left are modes that influence how the adjacent sheets behave when you resize a sheet.
When you resize a sheet you can push the adjacent sheets. 
When you resize a sheet you can't push adjacent sheets, the position of the adjacent sheets is locked. 
The magnet sets the behavior of the sheets and clips to one another. Long-touch on the magnet to remove all empty spaces in the current layer or selected layers/sheets/clips.
Combine these 2 modes to push and drag neighbor sheets/clips without adding or removing empty spaces.
Touch and hold the magnet to remove the gaps by moving the sheets/clips.
Combine these 2 modes to prevent you from moving neighbors or removing empty spaces.
Touch and hold the magnet to remove the gaps by increasing the length of the sheets/clips. The options on the right change the focus with the zoom and position in the timeline.
Tap on this icon to reset the Timeline scale and position. 
Tap on this icon to zoom at the position of the current frame. 
Tap on this icon to adjust the Timeline to fit all the layers' content, or the selected sheets. 
The informative text under the layers changes according to the situation.
If nothing is selected in the timeline, it will display the length of the shot and the number of sheets.
If you move the current frame, it will display the length of the current sheet and its position.
If one or several sheet(s) are selected, it will display the number of sheet(s) and their range in frame length and position.
If you go to another layer, it will display the length of the layer in number of frames, and the number of sheets contained in the layer.
A timestamp is displayed when you play the animation.
